Enumeration techniques can be really useful in surprising situations.

I am working on a planetary terrain rendering system for a game about spaceflight. The technique is based on conforming quadtrees but at no point there is an actual tree structure, it is encoded in a single integer. Starting from an origin point, the tree is traversed by moving to the adjacent subtree or parent node using simple bit twiddling.

The goal is to write a vertex shader than can efficiently generate triangle number n in quadtree m. This will be then fed to tesselation shaders for LOD subdivision.